1. Field of the Invention
The present invention relates to the field of LCD panel manufacturing. More particularly, the invention relates to a method for preventing seal damage in ODF LCD panel manufacturing.
2. Description of the Related Art
One Drop Fill (ODF) process has become a new form of LCD panel manufacturing. FIG. 1 shows an equipment currently used for ODF LCD panel manufacture. The equipment may be a press machine having an upper chuck 14 and a lower chuck 15 in a vacuum chamber 13, wherein at least one of the chucks is movable. The equipment may also be provided with an image recognition camera (not illustrated). The operation of the equipment as illustrated in FIG. 1 is described hereinafter. First, one substrate 12 is held by the lower chuck 15, and the other substrate 11 is held by the vacuum formed of the upper chuck 14. Then, after decreasing the air pressure inside the vacuum chamber 13 to a predetermined vacuum level; alignment of the upper side substrate 11 and the lower side substrate 12 is performed to a predetermined accuracy referring to the alignment marks (not shown) by a rotational member 16, and pressure is applied to the chucks 14 and 15 until the gap between the two substrates reaches a predetermined thickness, and the chamber 13 is brought to atmospheric air pressure through an air-removal hole 17.
However, to prevent disadvantages that might occur owing to the sudden change in pressure such as damage to the seals, unevenness of gap thickness, and even contamination of liquid crystal and LCD active areas, an extra seal pattern 22 is usually applied along the periphery of the substrate 21 as shown in FIG. 2, one or two seal patterns 24 are usually applied on the outer side of the original seal pattern 23, and a cross seal pattern 25 is applied between each TFT-array area to block air entry that might destroy the TFT-array areas when the seal pattern 23 is damaged.
The above methods to prevent damage to the seal patterns still have shortcomings, for example, a longer time is required to apply the extra seal patterns, thus increasing the tact time of LCD panel manufacture; the seal patterns are not cured from the change in pressure such that the air blockage is not high sufficient and bubbles may occur. Furthermore, application of a seal pattern must usually maintain a minimum distance of about 10 mm from other seal patterns to maintain best performance, therefore, too many seal patterns on the substrate can limit the number of TFT-array areas that can be formed thereon and may also cause chipping, breaking the substrate.